skip to main content

TKI/ICI Thyroid Toxicity — SCE Medical Oncology MCQ

Instant feedback + full explanation. One question, done properly.

HardImmunotherapy & Targeted TherapyTKI/ICI Thyroid ToxicitySCE Medical Oncology

A patient with metastatic renal cell carcinoma on lenvatinib + pembrolizumab develops a thyroid storm (severe thyrotoxicosis with tachycardia, fever and agitation) 6 weeks into treatment. Both drugs can cause thyroid dysfunction. What is the most likely mechanism?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Lenvatinib-induced destructive thyroiditis (thyroid follicular cell damage)

Both VEGFR-TKIs (lenvatinib, sunitinib) and ICIs (pembrolizumab) can cause thyroid dysfunction, but by different mechanisms. VEGFR-TKIs cause destructive thyroiditis through vascular damage to thyroid follicles, leading to a transient thyrotoxic phase (hormone release from damaged follicles) followed by hypothyroidism. ICI-induced thyroiditis is immune-mediated. Early thyrotoxicosis from destructive thyroiditis is typically self-limiting; treatment is supportive (beta-blockers). The subsequent hypothyroid phase requires levothyroxine.

Reference: BNF Lenvatinib monograph; ESMO 2024 Endocrine irAE and TKI toxicity Guidelines